package com.amt.util;

import com.amt.exception.InterfaceParamException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import sun.misc.BASE64Decoder;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import java.math.BigInteger;

/**   
 * @Title: AESUtil.java 
 * @Package com.amt.util 
 * @Description: TODO(AES算法工具类) 
 * @author 江伟  
 * @date 2020年3月16日 上午10:43:47 
 * Copyright (c) ©1994-2021 Scjydz.com All Rights Reserved.
 */
@SuppressWarnings("restriction")
@Component
public class AESUtil {

    @Autowired
    private RedisTemplateUtil redisTemplateUtil;
    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";//默认的加密算法

    /**
     * aes解密
     * @param encrypt   内容
     * @return
     * @throws Exception
     */
    public String aesDecrypt(String encrypt) {
        try {
            return aesDecrypt(encrypt, redisTemplateUtil.getAESKey());
        } catch (Exception e) {
            throw new InterfaceParamException(e);
        }
    }  
 
    /**
     * aes加密
     * @param content
     * @return
     * @throws Exception
     */
    public String aesEncrypt(String content) {
        try {
            return aesEncrypt(content, redisTemplateUtil.getAESKey());
        } catch (Exception e) {
        	throw new InterfaceParamException(e);
        }
    }  
 
    /**
     * 将byte[]转为各种进制的字符串
     * @param bytes byte[]
     * @param radix 可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制
     * @return 转换后的字符串
     */
    public static String binary(byte[] bytes, int radix){
        return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数
    }  
 
    /**
     * base 64 encode
     * @param bytes 待编码的byte[]
     * @return 编码后的base 64 code
     */
    public String base64Encode(byte[] bytes){
        return Base64.encodeBase64String(bytes);
    }  
 
    /**
     * base 64 decode
     * @param base64Code 待解码的base 64 code
     * @return 解码后的byte[]
     * @throws Exception
     */
    public byte[] base64Decode(String base64Code) throws Exception{
        return StringUtils.isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
    }  
 
    /**
     * AES加密
     * @param content 待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的byte[]
     */
    public byte[] aesEncryptToBytes(String content, String encryptKey) {
        KeyGenerator kgen;
		try {
			kgen = KeyGenerator.getInstance("AES");
			kgen.init(128);
	        Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
	        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), "AES"));  
	        return cipher.doFinal(content.getBytes("utf-8"));
		} catch (Exception e) {
			 throw new InterfaceParamException(e);
		}
        
    }  
 
    /**
     * AES加密为base 64 code
     * @param content 待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的base 64 code
     */
    public String aesEncrypt(String content, String encryptKey) {
        return base64Encode(aesEncryptToBytes(content, encryptKey));
    }  
 
    /**
     * AES解密
     * @param encryptBytes 待解密的byte[]
     * @param decryptKey 解密密钥
     * @return 解密后的String
     */
    public String aesDecryptByBytes(byte[] encryptBytes, String decryptKey)  {
        KeyGenerator kgen;
		try {
			kgen = KeyGenerator.getInstance("AES");
			kgen.init(128);  
	        Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
	        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), "AES"));
	        byte[] decryptBytes = cipher.doFinal(encryptBytes);
	        return new String(decryptBytes);
		} catch (Exception e) {
			throw new InterfaceParamException(e);
		}
        
    }  
 
    /**
     * 将base 64 code AES解密
     * @param encryptStr 待解密的base 64 code
     * @param decryptKey 解密密钥
     * @return 解密后的string
     * @throws Exception
     */
    public String aesDecrypt(String encryptStr, String decryptKey)  {
        try {
			return StringUtils.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
		} catch (Exception e) {
			 throw new InterfaceParamException(e);
		}
    }  

}
